An article storage system is known which includes a pair of article storage shelves facing each other and a stacker crane traveling in a moving space formed between the pair of article storage shelves for transporting an article. In such an article storage system, an attached apparatus may be mounted in the vicinity of one side of the moving space in a width direction at a predetermined level lower than the stacker crane. As the attached apparatus, a transport device may be provided for supplying or delivering the article to/from an upper part of the article storage system, or a platform may be provided for the operator to access the upper part of the moving space from one side of the moving space in the width direction (first end side of a transverse direction) for maintenance work, for example.
Japanese Unexamined Patent Application Publication No. 2008-068963 (Patent Document 1) discloses an example of the above-noted article storage system, in which the transport device acting as the attached apparatus is provided for supplying or delivering the article to/from the upper part of the article storage system.
In the article storage system disclosed in Patent Document 1, the maintenance work for the stacker crane, if minor like inspection, can be performed with the stacker crane being positioned in the moving space. On the other hand, it is difficult for the operator to perform the maintenance work with the stacker crane being positioned in the moving space if some major maintenance work has to be done including exchange of a propelling motor for propelling a traveling carriage, exchange of a lifting motor for raising or lowering a lift deck, or exchange of the lift deck, for example. Thus, the stacker crane should be moved along a longitudinal direction of the moving space and carried out from the moving space to perform the maintenance work in the outside of the moving space, and then returned or carried in to the moving space after the maintenance work is completed.
In the article storage system as disclosed in Patent Document 1, if the other side of the moving space in the longitudinal direction (a second end side of the transverse direction opposite to the first end side of the transverse direction) is blocked with a pillar of a structure building, or equipment or a device provided in its vicinity, for example, the stacker crane cannot be carried out to the outside from the other side of the moving space in the longitudinal direction. As a result, the stacker crane should be carried out to the outside from the first end side of the transverse direction in such an article storage system. In that case, however, the attached apparatus is mounted in the vicinity of the first end side of the moving space in the transverse direction as noted above at a level lower than the stacker crane, which prevents the stacker crane from being carried out from the moving space if the attached apparatus is mounted. Hence, the attached apparatus has to be removed before the stacker crane is carried out from the first end side of the moving space in the transverse direction. Further, it is necessary to mount the attached apparatus in the system after the stacker crane is returned or carried in from the first end side of the moving space in the transverse direction, which requires much time and effort for carrying in or out the stacker crane from the moving space and makes it difficult for the operator to perform the maintenance work for the stacker crane that requires a large space.